Firefox 3.1 beta 1 officially released

First beta of Firefox 3.1, its next major browser release. You can grab the beta right here on mozilla.com in Windows, Mac OS X, and Linux flavors. Little has changed compared to Firefox 3 from a cosmetic standpoint, although you’ll encounter new features like the graphical tab switcher (brought up by hitting CTRL-TAB with a few tabs open). Mozilla developers seem to have focused the bulk of their efforts on under-the-hood changes, like the addition of the TraceMonkey JavaScript rendering engine. TraceMonkey isn’t on by default because of reliability concerns, Ars says, but you can enable it by typing “about:config” in the address bar, finding the “javascript.options.jit.content” variable, and setting it to “true.”